SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cabc82a32841ba845acc7cd0353ccfea00e65c3d0132958727806c3f6e084c01' 
  AND token = 'c1CPRoTImoEYcY/if44y1RpWf62IZPTvnzArxGPEFPY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}